Oubliette Escape Room Puzzle

An electromechanical puzzle for an escape room.

My friends at Oubliette Entertainments ran a successful escape room in Brixton in 2016. Based on an earlier install in Portland, they wanted to overhaul a few puzzles for the London installation.

I worked on the hardware and firmware for a specific electronic puzzle. Originally, this had been based on discrete wiring and components, which meant that there were inadvertently too many ways to solve it - there should only have been one!

I rebuilt the puzzle based around an Arduino Mega 2560, with illuminating toggle switches. By moving to a microcontroller it was possible to check the switches in the puzzle to confirm that only the correct solution worked. Dave Aldhouse was working on the physical build for the puzzle; he gave me a laser-cut maquette to mount the switches in whilst I worked, and to confirm we’d got our measurements correct.

The microcontroller also allowed me to interface with another electromechanical part of the puzzle - a card slot. Engineer Mike Potter had built our ingenious card mechanism with a pair of servo motors, controlled by an Arduino. I incorporated his Arduino code into mine, and the puzzle now had control of the card slot depending on whether the answer was right or not.

Then, some polish. Lights and a buzzer made it clear to players if they’d got their answer right or wrong. I made sure the puzzle only worked when a card was in the slot - which meant it wouldn’t function fully until players had reached this stage of the room. And finally, I made sure that once it had been successfully completed, it disabled itself until it was power-cycled by the event staff - not being needed again in the escape process!

All that remained was the install. Dave had built our casing, designed to be swung open for maintenance; he mounted the card mechanism, and I installed our electronics and components. Crimped terminals made swapping switches possible, and made installation much easier. After some fettling, the puzzle ran well for the duration of the run.

A fun project - I co-ordinated with Mink and Dave at Oubliette throughout, ordering parts, finding which switches would best suit their aesthetic, and making the install as foolproof as possible for the event managers to maintain.